In this photo taken June, 19, 2012, a Black-necked Stilt is seen in a rice field near Williams, Calif. More than 165 California rice farmers have signed up for an incentive program, funded by a $2 million US. Natural Resources Conservation Service, to make habitat improvements in their rice paddies to provide migratory and water birds a place to stop, feed and breed.(AP Photo/Rich Pedroncelli)

Photo: Rich Pedroncelli, Associated Press

In this photo taken June, 19, 2012, a Black-necked Stilt is seen...

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In this photo taken June, 19, 2012, the eggs of a Black-necked Stilt sit in a nest on a rice field levee near Williams, Calif. More than 165 California rice farmers have signed up for an incentive program, funded by a $2 million US. Natural Resources Conservation Service, to make habitat improvements in their rice paddies to provide migratory and water birds a place to stop, feed and breed.(AP Photo/Rich Pedroncelli)

The rust-orange head of an American avocet darted back and forth watching for predators, its black-and-white feathered body plopped atop a nest of four speckled eggs that lay on an earthen levee in a California rice paddy.

"It's a full clutch of four eggs," said Monica Iglecia, a shorebird biologist with Audubon California, looking through binoculars. "This is why we do this work. It's exciting to see."

The hundreds of vast, flooded rice paddies that cover miles of interior Northern California may seem like an unlikely safe haven for shorebirds, but changes occurring in the state's rice country may help improve the outlook for dozens of species in decline in recent decades. So far, more than 165 rice farmers have signed up for an incentive program that will build a system of islands and other habitat improvements in their paddies, and provide birds like the avocet a place to rest, feed and breed throughout the year.

The incentive, funded by $2 million from the U.S. Natural Resources Conservation Service, helps defray the costs of building the islands or of new equipment needed to make levees and other farm infrastructure more amenable as habitat.

California's rice farms lie in a region where about 95 percent of the native wetlands that once provided habitat for migratory and water birds have disappeared. The state's rice paddies, which produce much of the sushi rice consumed in the United States, take up more than a half million acres in the Sacramento Valley while protected wetlands cover a little more than 77,000 acres.

Even with shrinking wetlands, this valley that stretches from the state capital north about 160 miles to Redding is a part-time home to cinnamon-teal ducks, dowitchers, dunlins, black-necked stilts and dozens of other migratory water birds.

Migratory birds face a number of perils, not least among them the effects of climate change, which is expected to reduce the Sierra Nevada snowpack and the amount of water feeding the remaining wetlands, said Khara Strum, a water bird ecologist with PRBO Conservation Science.

As natural bird habitat dwindles, California's Sacramento Valley falls under a flight pattern known as the Pacific Flyway, a major route for migratory birds that stretches from Alaska to Patagonia. So biologists see a significant opportunity in adding to and improving habitat on the only other wetlands that proliferate here: rice farms.